Bodies of water are used for many purposes including, for example, transportation, electricity generation, waste management, agricultural, industrial, or domestic water supply, or recreation. Bodies of water are often managed, regulated, or altered to permit or enhance these uses.
Conventional modifications to bodies of water or surrounding area may include bridges, beaches, buildings, quarries, aqueducts, water intake piping, dams that retain or contain water, levees that prevent water from flowing into a specific region, canals that connect one or more bodies of water, locks that permit raising and lowering of boats between stretches of water on different levels, water-powered electricity facilities, sewage treatment facilities, or water treatment facilities, to name a few.
Many such conventional modifications to water bodies change the conditions for the organisms that live in or near those water bodies. Such modifications that include physical structures in or around the water are termed “obstructions” for purposes of this application. Some such obstructions restrict or alter the movement or natural migratory routes of certain organisms. For example, certain fish migrate to find a suitable habitat for reproduction, protection, offspring, finding food, avoiding predators, increasing or decreasing exposure to light, finding water of a particular temperature, or other.
To facilitate fish migration and thereby lessen the deleterious effect an obstruction may have, many aquatic obstructions are built to include or are retrofitted to include a fish passageway around the obstruction. Certain disadvantages are associated with known passageways. For example, certain known fish passageways include an enclosure having no pressure regulation. Such embodiments may require fish to endure abrupt transitions from high-pressure environment to low-pressure environment or low-pressure environment to high-pressure environment or through high-pressure passageways, which may result in harm to the fish. Other known fish passageways regulate the pressure in the enclosure such that the transition is less abrupt. However, such pressure-regulating passageways often require substantial changes in vertical position of the fish within the enclosure. Such changes in vertical position may require construction of prohibitively large and expensive structures.
In addition, certain known fish passageways include an enclosure in which the speed and velocity of water flow in the passageway is uncontrollable. In such passageways, the uncontrolled water flow may reach high water flow speeds, which increases the risk of harm to the fish.
Still other known fish passageways include an enclosure that permits passage of any and all types of fish and any and all water contents at the same time. Examples of such fish passageways include a fish ladder or a fish elevator. A typical fish ladder is a structure that permits fish to swim up, jump up, or pass down a series of relatively low steps and eventually into the water on the other side. A fish elevator includes an enclosure into which water contents enter, and the water level and all of the water contents are raised or lowered to clear the obstruction.
Certain disadvantages are associated with fish ladders and fish elevators. Construction of fish ladders and fish elevators at high-head dams often requires construction of large, expensive structures, which may be prohibitively expensive for smaller capacity hydroelectric projects. Small fish may pass through the enclosure at the same time as larger predatory fish, which puts the small fish at risk of harm.
Accordingly, there is a demand for a reduced cost system and methods that permits controlling pressure and water flow through an environment positioned to transition fish and other aquatic organisms around an aquatic obstruction. The present invention satisfies this demand.